The first paragraph is strictly a description of the physical setting of the farm, filled with descriptive devices that help to really seat the reader in the scene. Steinbeck does not simply use colors and physical shapes to describe the scene, he personifies the mountains as they "stood up against the sky." He compared the farm buildings to aphids clinging to a plant in the way that they cling to the rocky, shallow soil.
He also describes the shack and the barn as being "grey-bitten with sea salt" to give the setting some history and the feeling of being attacked and worn down by the weather and the power of nature over the years. The animals "stocked the place" and the sense of the farm being a passive object acted upon by both the weather and the people is created in the last couple sentences.